(āng'strəm) A unit of length equal to one hundred-millionth (10-10) of a meter. It was once used to measure wavelengths of light and the diameters of atoms, but has now been mostly replaced by the nanometer.

Ångström

(āng'strəm) Swedish physicist and astronomer who pioneered the use of the spectroscope in the analysis of radiation. By studying the spectrum of visible light given off by the Sun, Ångström discovered that there is hydrogen in the Sun's atmosphere. The angstrom unit of measurement is named for him.